dt-bindings: usb: dwc2: Add reference to usb-drd.yaml

Add a reference to usb-drd.yaml, in order to:
- extend possible supported properties
- avoid duplicated definitions of standard properties
Remove definitions for dr_mode and usb-role-switch standard properties.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/1634133425-25670-2-git-send-email-fabrice.gasnier@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/usb/dwc2.yaml

@@ -9,6 +9,9 @@ title: DesignWare HS OTG USB 2.0 controller Bindings
 maintainers:
   - Rob Herring <robh@kernel.org>
 
+allOf:
+  - $ref: usb-drd.yaml#
+
 properties:
   compatible:
     oneOf:
@@ -101,12 +104,9 @@ properties:
     description: reference to the VBUS and ID sensing comparators supply, in
       order to perform OTG operation, used on STM32MP15 SoCs.
 
-  dr_mode:
-    enum: [host, peripheral, otg]
+  dr_mode: true
 
-  usb-role-switch:
-    $ref: /schemas/types.yaml#/definitions/flag
-    description: Support role switch.
+  usb-role-switch: true
 
   g-rx-fifo-size:
     $ref: /schemas/types.yaml#/definitions/uint32